System and method of variable equalization for crosstalk minimization

ABSTRACT

An information handling system transmitter has a channel management module configured to negotiate and to lock a static transmitter equalization range. Control logic selects a setting adjustment for the locked transmitter equalization range; selects a variation type; applies the selected setting adjustment using the selected variation type, and instructs the transmitter channel management module to re-negotiate the updated transmitter equalization range. A receiver may negotiate and re-negotiate with the transmitter in order to receive the updated transmitter equalization range. The receiver may auto-adapt the updated transmitter equalization range to receive the transmitted data.

FIELD OF THE DISCLOSURE

This disclosure generally relates to information handling systems, andmore particularly relates to variable equalization for crosstalkminimization in a serial channel of an information handling system.

BACKGROUND

As the value and use of information continues to increase, individualsand businesses seek additional ways to process and store information.One option is an information handling system. An information handlingsystem generally processes, compiles, stores, and/or communicatesinformation or data for business, personal, or other purposes. Becausetechnology and information handling needs and requirements may varybetween different applications, information handling systems may alsovary regarding what information is handled, how the information ishandled, how much information is processed, stored, or communicated, andhow quickly and efficiently the information may be processed, stored, orcommunicated. The variations in information handling systems allow forinformation handling systems to be general or configured for a specificuser or specific use such as financial transaction processing,reservations, enterprise data storage, or global communications. Inaddition, information handling systems may include a variety of hardwareand software resources that may be configured to process, store, andcommunicate information and may include one or more computer systems,data storage systems, and networking systems.

SUMMARY

An information handling system includes a transmitter and a receiver.The transmitter may have a channel management module configured tonegotiate and to lock a static transmitter equalization range. Controllogic may select a setting adjustment for the locked transmitterequalization range; select a variation type; apply the selected settingadjustment using the selected variation type, and instruct thetransmitter channel management module to re-negotiate the updatedtransmitter equalization range. The receiver may negotiate andre-negotiate with the transmitter in order to receive the updatedtransmitter equalization range. The receiver may auto-adapt the updatedtransmitter equalization range to receive the transmitted data.

BRIEF DESCRIPTION OF THE DRAWINGS

It will be appreciated that for simplicity and clarity of illustration,elements illustrated in the Figures have not necessarily been drawn toscale. For example, the dimensions of some of the elements areexaggerated relative to other elements. Embodiments incorporatingteachings of the present disclosure are shown and described with respectto the drawings presented herein, in which:

FIG. 1 illustrates a high speed serial interface according to anembodiment of the present disclosure;

FIG. 2 illustrates a portion of the high speed serial interface thatimplements variable equalization to minimize crosstalk;

FIG. 3 is a graph showing an application of identical transmitterequalization ranges across all lanes of a transmission channel;

FIG. 4 is a graph showing an application of different transmitterequalization ranges between different lanes of a transmission channel;

FIG. 5 is a flowchart illustrating a method of minimizing crosstalk byusing variable equalization in a serial channel according to anembodiment of the present disclosure; and

FIG. 6 is a block diagram illustrating a generalized informationhandling system according to an embodiment of the present disclosure.

The use of the same reference symbols in different drawings indicatessimilar or identical items.

DETAILED DESCRIPTION OF DRAWINGS

The following description in combination with the Figures is provided toassist in understanding the teachings disclosed herein. The followingdiscussion will focus on specific implementations and embodiments of theteachings. This focus is provided to assist in describing the teachings,and should not be interpreted as a limitation on the scope orapplicability of the teachings. However, other teachings can certainlybe used in this application. The teachings can also be used in otherapplications, and with several different types of architectures, such asdistributed computing architectures, client/server architectures, ormiddleware server architectures and associated resources.

FIG. 1 illustrates an embodiment of a high speed serial channel 100 ofan information handling system. Serial channel 100 includes atransmitter 110, a transmission channel 120, and a receiver 130. Serialchannel 100 represents one half of a bi-directional serial data link forcommunicating data from transmitter 110 located at a first component toreceiver 130 located at a second component. The other half of thebi-directional serial data link is similar to serial channel 100, butwith a receiver in the first component, and a transmitter in the secondcomponent, for communicating data back from the second component to thefirst component. Here, the components can be understood to includeelements within an information handling system, such as components thatare attached to one or more printed circuit board of the informationhandling system, where transmission channel 120 can represent one ormore circuit traces on the printed circuit board, and can include one ormore connectors. The components can also be understood to includedevices of an information handling system, such as a hard drive, astorage array, a processor, and the like, that are separate from theprinted circuit board of the information handling system, wheretransmission channel 120 can include one or more transmission cables. Anexample of serial channel 100 includes a peripheral componentinterconnect (PCI)-Express (PCIe) channel that is in compliance with oneor more PCIe specifications, a Serial ATA (SATA) channel that is incompliance with one or more SATA specifications, a SAS channel that isin compliance with one or more SAS specifications, or another high speedserial channel.

Serial channel 100 operates to provide back channel adaptation wheretransmitter 110 and receiver 130 communicate with each other to optimizeand adjust various compensation values within the transmitter and thereceiver to compensate for insertion loss, crosstalk, and other signaldegradations of transmission channel 120. In a preferred embodiment, theback channel adaptation mechanism may operate to provide dynamic settingadjustments of a transmitter equalization range in each lane or acrossall lanes of a multiple lane-transmission channel. In this embodiment,the different setting adjustments may be applied randomly, uniformly, orby using Gaussian distribution. In this manner, the compensation valueor equalization value at any point in time within a given equalizationrange of a particular lane may not be aligned to the equalization valueat any point in time within an identical or a different equalizationrange in another lane. In case of alignment between these equalizationvalues, the alignment includes a very short duration and may create anegligible crosstalk amount. As a result, the non-alignment from thevarying equalization values may minimize presence of crosstalk inbetween lanes or in the transmitter channel. At the receiver end, thereceiver 130 may correspondingly adapt to non-static setting of thetransmitter equalization range by adjusting accordingly the receiverequalization parameters.

Transmitter 110 includes a channel output module 112, a feed-forwardequalization (FFE) continuous time linear equalization (CTLE) module114, a transmitter channel management module 116, and a transmittercontrol logic 118. Receiver 130 includes a CTLE module 134, an automaticgain control (AGC) module 136, a decision feedback equalization (DFE)module 138, a receiver control logic module 140, and a receiver channelmanagement module 142.

Channel output module 112 includes an impedance/tuning setting. Theimpedance setting operates to select a target impedance for the outputof transmitter 110. For example, the impedance setting can operate toselect a 25 ohm output impedance, a 40 ohm output impedance, a 50 ohmoutput impedance, a 75 ohm output impedance, or another output impedanceselected to match an impedance of transmission channel 120, as needed ordesired. The tuning setting operates to select a fine tuning of theoutput impedance of transmitter 110 around the nominal impedanceselected by the impedance setting. In a particular embodiment, thetuning setting provides a low impedance adjustment setting, a nominalsetting, and a high impedance adjustment setting. In another embodiment,the tuning setting provides more or less than three impedance adjustmentsettings, as needed or desired. In these embodiments, the channel outputmodule may be configured to adapt dynamic changes or adjustments in thesettings of transmitter equalization parameters. Particularly, thechannel output module is configured to adapt the randomly, uniformly,etc. distributed setting adjustments that are used during actual datatransmissions in the transmitter channel.

Transmitter channel management module 116 and receiver channelmanagement module 142 may represent a separate side-band communicationchannel for communicating back channel adaptation instructions betweentransmitter 110 and receiver 130. For example, the communicationsbetween transmitter channel management module 116 and receiver channelmanagement module 142 may include a third party device or mechanism thatprovides system management for an information handling system thatincludes serial channel 100, such as a Baseboard Management Controller(BMC), an Integrated Dell Remote Access Controller (IDRAC), or anotherembedded controller, as needed or desired. In another embodiment,management module 116 and channel management module 142 may representmanagement traffic between transmitter 110 and receiver 130 that iscommunicated over transmission channel 120 and an additionaltransmission channel from receiver 130 to transmitter 110.

In an embodiment, the transmitter channel management module may beconfigured to negotiate with the receiver channel management module inorder to receive and to lock an initial and static transmitterequalization parameter. Thereafter, transmitter control logic 118 isconfigured to process the static transmitter equalization parameter togenerate an updated transmitter equalization parameter. With the updatedtransmitter equalization parameter, the transmitter channel managementmodule re-negotiates or performs another negotiation with receiverchannel management module. In response to the re-negotiated transmitterequalization parameter, the receiver control logic 140 may facilitateadjustments in receiver equalization parameter based on the updatedtransmitter equalization parameter. In an embodiment, the transmitterchannel management module 116 exits after each negotiation and thereceiver auto-adapts to the latest or updated transmitter equalizationparameter.

Transmitter equalization using the FFE CTLE module 114 providespre-emphasis of high frequency leading edge of bit transitions. In anembodiment, the FFE CTLE module may provide emphasis in its highfrequency response. In this embodiment, the FFE CTLE module may beimplemented by using delays, gains, and summer components. In aparticular embodiment, the FFE CTLE module is a finite impulse response(FIR) filter. For example, input data propagates through a series of FFECTLE module delay lines where each delay is equal to one bit unit timeinterval. In this example, each of the sampled signals is multiplied bycorresponding FIR tap coefficient, and thereafter the resulting productsfrom the FIR taps are summed up to produce the FFE CTLE module output.

The FFE CTLE module output may be configured to correspond to thedynamic adjustments in the setting of the transmitter equalizationparameter such as transmitter equalization range. In this embodiment,FFE CTLE may provide emphasis-equalizations that are not limited to astatic equalization range such as a 5 dB equalization range, 4 dBequalization range, and the like. With dynamic setting adjustments thatare applied in random, uniform, or by using Gaussian distribution, thetime-varying filter frequency responses of the FFE CTLE may generatedifferent amount of equalization values at any point in time within agiven equalization range.

For example, the FFE CTLE module provides pre-emphasis on a 4 db-6 dbequalization range. The 4 db-6 db equalization range includes, forexample, the updated transmitter equalization parameter after a selected+−1 dB setting adjustment is applied to a 5 dB static referenceequalization range. In this example, the +−1 dB setting adjustment isapplied in random, uniform, or by using Gaussian distribution. In thisexample still, the pre-emphasis may generate different equalizationvalues at any point in time within the 4 db-6 db equalization rangebecause of time-varying filter frequency responses of the FFE CTLEmodule. Because the corresponding switching frequencies for the varyingequalization values are not static, the performed equalizations mayminimize occurrence of crosstalk. In a particular embodiment, the FFECTLE module may receive control signals from the transmitter controllogic module. In this embodiment, the control signals may includeinstructions to implement the updated equalization ranges or parameters.

Transmitter control logic module 118 includes a hardware circuitryconfigured to provide the dynamic setting adjustments of the transmitterequalization parameters as described herein. Transmitter control logicmodule 118 may utilize instructions that are hard coded into transmitteror firmware that may be stored in the transmitter or provided thereto,as needed or desired. In an embodiment, the transmitter control logicmodule provides instructions to the transmitter channel management tonegotiate and to lock the initial equalization parameters. In thisembodiment, the transmitter control logic module receives the lockedinitial equalization parameters, selects a desired setting adjustment,and performs dynamic setting adjustments of the locked initialequalization parameters. The dynamic setting adjustment is applied inrandom, uniform, or by using Gaussian distribution.

In an embodiment, the negotiated and locked initial equalizationparameters may include a particular static reference equalization range,a corresponding operating or switching frequency for the staticequalization range, a lane width, a link bandwidth, a transmitterde-emphasis level ratio, and the like. In this embodiment, the dynamicsetting adjustments may include varying in random, uniform, or by usingGaussian distribution, the static equalization range, link bandwidth andthe like. For example the dynamic setting adjustments may includeselecting a pre-set value, such as +−3 dB, that is added and subtractedto the reference static equalization range e.g., 5 dB in order togenerate the updated equalization range. In this example, the selected+/−3 dB setting adjustment is applied in random, uniform, or distributedusing Gaussian distribution. Furthermore, the updated equalization rangemay be identical on each lane. In case of different pre-set values thatare applied to the static equalization range, each of resulting updatedequalization ranges may be applied on each lane of transmission channel.Thereafter, the transmitter control logic module issues anotherinstruction for the transmitter channel management to re-negotiate theupdated equalization range. With the receiver auto-adapting there-negotiated equalization range, the transmitter performs datatransmissions through the transmission channel.

In another embodiment, the transmitter control logic module need notperform the initial negotiation or auto-negotiation to lock on theinitial transmitter equalization range when the link has beenestablished. Instead, the transmitter control logic module may beconfigured to directly negotiate the updated equalization ranges. Inthis embodiment, the receiver is expected to auto-adapt accordingly.

Transmission channel link may include multiple lane widths such as afour-lane (x4) root port, an eight-lane (x8) root port, a singlesixteen-lane (x16) root port, a thirty two-lane (x32) root port, or acombination thereof. In an embodiment, the updated equalizationparameter such as updated equalization range may be implemented acrossall lanes of a particular root port. For example, for the x4 root port,an updated equalization range may include a setting adjustment of +−1 dBon a negotiated and locked 5 dB initial static equalization range. Inthis example, the setting adjustment of +−1 dB is implemented across allfour lanes of the x4 root port. That is, each of the lanes 0, 1, 2 and 3of the x4 root port may include 4 dB to 6 dB—updated equalization range.The 4 dB to 6 dB equalization range is derived from subtracting andadding 1 dB, respectively, to the locked 5 dB static equalization range.Furthermore, the +−1 dB setting adjustment is applied in random,uniform, and the like, in order to generate varying differentequalization values within the 4 dB to 6 dB equalization range.

In another embodiment, different setting adjustments may be selected andapplied for each lane of the x4 root port in order to generate differentspread. In this embodiment, each lane may include a different settingadjustment. For example, for a locked 5 dB initial static equalizationrange, a +/−1 dB may be selected and applied to lane 0, +/−1.5 db may beselected and applied to lane 1, +/−2 dB may be selected and applied tolane 2, and +/−2.5 db may be selected and applied to lane 3. In thisexample, each of the lanes 0, 1, 2, and 3 of the x4 root port includesan equalization range of 4 dB-5 dB, 3.5 dB-6.5 dB, 3 dB-7 dB, and 2.5dB-7.5 dB, respectively. In this example still, the selected settingadjustments are applied in random, uniform, or by using Gaussiandistribution. As a result, the different equalization values at anypoint in time within a given equalization range may decrease presence ofcrosstalk in the transmission channel.

Receiver 130 receives serial data transmission through the CTLE module134. In an embodiment, the CTLE module operates to provide compensationfor inter-signal interference (ISI) in order to open the signal eye ofthe received signal. The amount of compensation is determined based uponthe adapted updated equalization parameters in the transmitter 110. Forexample, the updated equalization range is received by the receivercontrol logic 140 through the receiver channel management module 142. Inthis example, the receiver control logic may issue instructions to theCTLE module to adapt the updated equalization range. For example, theCTLE module supports 21 CTLE equalization settings where each settingprescribes a different amount of equalization, from 0 dB to 10 dB, in0.5 dB steps. In this example, the CTLE module may utilize theequalization setting that corresponds to the updated equalizationparameters used at the transmitting side. In other examples, differentnumbers of settings and amounts of equalization may be utilized, asneeded or desired.

The equalized signal is provided from CTLE module 134 to AGC module 136.AGC module 136 operates to provide linear gain to the signal receivedfrom CTLE module 134 to further open the signal eye of the receivedsignal. The amount of gain is determined by a gain setting, and cansupport 21 gain settings where each setting prescribes a differentamount of gain, for example, from 0 dB to 10 dB, in 0.5 dB steps. Othernumbers of settings and amounts of gain prescribed by the gain settingcan be utilized, as needed or desired. In an embodiment, AGC 136operates to provide linear gain in two or more frequency ranges. Forexample, AGC 136 can include a first gain setting for low frequency gainand a second gain setting for high frequency gain, and each setting cansupport 21 gain settings which each prescribe a different amount ofgain, for example, from 0 dB to 10 dB, in 0.5 dB steps. Other numbers ofsettings and amounts of gain prescribed by the gain settings can beutilized, as needed or desired.

The amplified signal is provided from AGC module 136 to DFE module 138.DFE module 138 operates to provide feedback based compensation to thereceived signal. The amount of compensation is determined by enabling anumber of circuit feedback taps. For example, DFE module 138 can supportup to 16 taps that provide compensation based upon up to 16 previousdata points. In a particular embodiment, DFE module 138 can be turnedoff, thereby reducing the power consumed by receiver 130. In anotherembodiment, one or more tap of DFE module 138 can be turned on basedupon the taps setting, while the rest of the taps are placed into atri-state condition, that is, with power applied, but with the taps notproviding feedback to the resultant DFE compensation. In yet anotherembodiment, one or more tap of DFE module 138 can be turned on basedupon the taps setting, while the rest of the taps are turned off,thereby reducing the power consumed by receiver 130. Other numbers oftaps can be utilized, as needed or desired.

In an embodiment, the receiver control logic module 140 may beconfigured to issue instructions to the CTLE module, AGC, and the DFE,based upon the received updated equalization parameters through thereceiver channel management 142. For example, the re-negotiated updatedequalization parameter includes a particular equalization range that isapplied across all four lanes of the x4 transmission channel. In thisexample, the receiver control logic module may issue instructions forthe CTLE module, AGC, and the DFE to adapt the new equalizationparameters when receiving data transmissions across all lanes of the x4transmission channel. In this manner, the data transmissions arereceived with minimal crosstalk.

FIG. 2 shows a portion of the serial channel 100 including thetransmitter control logic 118 and the transmitter channel management116. The transmitter control logic 118 includes a setting selector andadjustor module 200, and a variation type selector 202. The transmittercontrol logic is further configured to receive an auto-negotiated staticequalization range 204, to process the received static equalizationrange in order to generate an updated equalization range 206, and toissue control signals 210 to implement the updated equalization range.The transmitter channel management module 116 includes a negotiatormodule 220 that is configured to negotiate and/or re-negotiate with thereceiver. For example, the initial negotiation facilitates receiving andlocking of the static equalization range while the re-negotiationincludes communicating the updated equalization range to the receiver.

In an embodiment, transmitter channel management module 116 receives aninstruction from the transmitter control logic to negotiate and to lockan initial static transmitter equalization range. Thereafter, thetransmitter channel management module sends the static equalizationrange 204 and waits for another instruction to re-negotiate the updatedequalization range 206. In this embodiment, the transmitter controllogic is configured to process the locked initial static equalizationrange by selecting first a setting adjustment, and thereafter applyingthe selected setting adjustments randomly, uniformly, or by usingGaussian distribution.

In an embodiment, the setting selector and adjustor module 200 isconfigured to use pre-defined values or a look-up table to obtain adesired setting adjustment. The desired setting adjustment may bederived by adding or subtracting the selected pre-defined value such as1 dB, 2 dB, etc. from the reference static equalization range. In thisembodiment, the variation type selector 202 is configured to select thevariation type and the setting adjustment may be applied using theselected variation type randomly, uniformly, or by using Gaussiandistribution.

In an embodiment, the control signals 210 may include instructions toimplement the updated equalization ranges in the lanes of thetransmission channel. For example, in the x4 root port, the controlsignal may implement the same equalization range across four lanes ofthe x4 root port, or the control signal may implement differentequalization ranges for each lane. In this example, the equalizationvalue at any point in time within an equalization range on one lane isdifferent from the equalization value at any point in time within asimilar equalization range or different equalization range in anotherlane.

FIG. 3 shows a graph 300 of an updated transmitter equalization rangethat is identically applied in each lane of an x4 root port. The graphincludes equalization values 302, 304, 306, and 308 for lanes 0, 1, 2,and 3, respectively, of the x4 root port. The equalization value mayinclude the emphasis-equalization provided by the FFE CTLE at any pointin time within an equalization range 320, which indicates the updatedequalization range after the processing of the initial staticequalization range as described in FIG. 2.

In an embodiment, the transmitter control logic may facilitategeneration of non-aligned equalization values 302, 304, 306, and 308, atany point in time within the equalization range 320. For example, for astatic reference equalization range of 5 dB, the setting selector andadjustor module 200 may select and apply +−1 dB to the initially locked5 dB. In this example, the application of the selected +−1 dB valuecreates the 4 dB to 6 dB equalization range that may be applied acrossall lanes of the x4 root port. Because of the random, uniform, orGaussian distribution that creates the time-varying frequency filterresponses in the FFE CTLE module, the equalization values 302, 304, 306,and 308 are not aligned with one another. This non-alignment minimizespresence of crosstalk in the x4root port.

FIG. 4 shows a graph 400 of different updated transmitter equalizationranges that are applied in a four-lane x4 root port. Graph 400 includesexample equalization values 402, 404, 406, and 408 in lanes 0, 1, 2, and3, respectively, of the x4 root port. The lanes 0, 1, 2, and 3 mayfurther include equalization ranges 420, 422, 424, and 426,respectively. The varying equalization ranges are generated from anapplication of different setting adjustments on each lane of the x4 rootport.

For example, for a static reference equalization value of 5 dB, thesetting selector and adjustor component may select and apply +−1 dB,+−1.5 dB, +−2 dB, and +−2.5 dB pre-set values to the 5 dB. In thisexample, the resulting equalization ranges 420, 422, 424, and 426 mayinclude 4 dB-5 dB, 3.5 dB-5.5 dB, 3 dB-7 dB, and 2.5 dB-7.5 dB ranges,respectively. In this example still, the different setting adjustmentsare applied randomly, uniformly, or by using Gaussian distribution.

In an embodiment, the transmitter control logic may facilitate thegeneration of non-aligned equalization values 402, 404, 406, and 408, atany point in time within the different equalization ranges 420, 422,424, and 426. In this embodiment, the non-alignment of the differentequalization values may minimize presence of crosstalk.

FIG. 5 shows a method 500 for using variable equalization to minimizecrosstalk in a serial channel of a system according to an embodiment ofthe present disclosure. At block 502, link training is begun where atransmitter and receiver in the system perform a back channel adaptionoperation. At block 504, the transmitter channel management modulenegotiates and locks a static transmitter equalization parameter. Atblock 506, the transmitter control logic selects a setting adjustmentfor the static transmitter equalization parameter. At block 508, thetransmitter control logic is configured to select a variation type. Atblock 510, the setting adjustment is implemented or applied using randomvariation, uniform variation, Gaussian method, or any other variationtypes. At block 512, the transmitter re-negotiates with the receiverwith regard to the updated transmitter equalization parameters. At block514, the receiver adapts the updated transmitter equalization parametersand accordingly adjusts its receiving parameters to receive transmitteddata.

FIG. 6 illustrates a generalized embodiment of information handlingsystem 600. For purpose of this disclosure information handling system600 can include any instrumentality or aggregate of instrumentalitiesoperable to compute, classify, process, transmit, receive, retrieve,originate, switch, store, display, manifest, detect, record, reproduce,handle, or utilize any form of information, intelligence, or data forbusiness, scientific, control, entertainment, or other purposes. Forexample, information handling system 600 can be a personal computer, alaptop computer, a smart phone, a tablet device or other consumerelectronic device, a network server, a network storage device, a switchrouter or other network communication device, or any other suitabledevice and may vary in size, shape, performance, functionality, andprice. Further, information handling system 600 can include processingresources for executing machine-executable code, such as a centralprocessing unit (CPU), a programmable logic array (PLA), an embeddeddevice such as a System-on-a-Chip (SoC), or other control logichardware. Information handling system 600 can also include one or morecomputer-readable medium for storing machine-executable code, such assoftware or data. Additional components of information handling system600 can include one or more storage devices that can storemachine-executable code, one or more communications ports forcommunicating with external devices, and various input and output (I/O)devices, such as a keyboard, a mouse, and a video display. Informationhandling system 600 can also include one or more buses operable totransmit information between the various hardware components.

Information handling system 600 can include devices or modules thatembody one or more of the devices or modules described above, andoperates to perform one or more of the methods described above. Forexample, the transmitter 110 may be a part of a processor while thereceiver 130 may be included in a disk controller. Information handlingsystem 600 includes the processors 602 and 604, a chipset 610, a memory620, a graphics interface 630, include a basic input and outputsystem/extensible firmware interface (BIOS/EFI) module 640, a diskcontroller 650, a disk emulator 660, an input/output (I/O) interface670, and a network interface 680. Processor 602 is connected to chipset610 via processor interface 606, and processor 604 is connected to thechipset via processor interface 608. Memory 620 is connected to chipset610 via a memory bus 622. Graphics interface 630 is connected to chipset610 via a graphics interface 632, and provides a video display output636 to a video display 634. In a particular embodiment, informationhandling system 600 includes separate memories that are dedicated toeach of processors 602 and 604 via separate memory interfaces. Anexample of memory 620 includes random access memory (RAM) such as staticRAM (SRAM), dynamic RAM (DRAM), non-volatile RAM (NV-RAM), or the like,read only memory (ROM), another type of memory, or a combinationthereof.

BIOS/EFI module 640, disk controller 650, and I/O interface 670 areconnected to chipset 610 via an I/O channel 612. An example of I/Ochannel 612 includes a PCI interface, a PCI-Extended (PCI-X) interface,a high-speed PCI-Express (PCIe) interface, another industry standard orproprietary communication interface, or a combination thereof. Chipset610 can also include one or more other I/O interfaces, including anIndustry Standard Architecture (ISA) interface, a Small Computer SerialInterface (SCSI) interface, an Inter-Integrated Circuit (I²C) interface,a System Packet Interface (SPI), a Universal Serial Bus (USB), anotherinterface, or a combination thereof. BIOS/EFI module 640 includesBIOS/EFI code operable to detect resources within information handlingsystem 600, to provide drivers for the resources, initialize theresources, and access the resources. BIOS/EFI module 640 includes codethat operates to detect resources within information handling system600, to provide drivers for the resources, to initialize the resources,and to access the resources.

Disk controller 650 includes a disk interface 652 that connects the disccontroller to a hard disk drive (HDD) 654, to an optical disk drive(ODD) 656, and to disk emulator 660. An example of disk interface 652includes an Integrated Drive Electronics (IDE) interface, an AdvancedTechnology Attachment (ATA) such as a parallel ATA (PATA) interface or aserial ATA (SATA) interface, a SCSI interface, a USB interface, aproprietary interface, or a combination thereof. Disk emulator 660permits a solid-state drive 664 to be connected to information handlingsystem 600 via an external interface 662. An example of externalinterface 662 includes a USB interface, an IEEE 1394 (Firewire)interface, a proprietary interface, or a combination thereof.Alternatively, solid-state drive 664 can be disposed within informationhandling system 600.

I/O interface 670 includes a peripheral interface 672 that connects theI/O interface to an add-on resource 674, to a TPM 676, and to networkinterface 680. Peripheral interface 672 can be the same type ofinterface as I/O channel 612, or can be a different type of interface.As such, I/O interface 670 extends the capacity of I/O channel 612 whenperipheral interface 672 and the I/O channel are of the same type, andthe I/O interface translates information from a format suitable to theI/O channel to a format suitable to the peripheral channel 672 when theyare of a different type. Add-on resource 674 can include a data storagesystem, an additional graphics interface, a network interface card(NIC), a sound/video processing card, another add-on resource, or acombination thereof. Add-on resource 674 can be on a main circuit board,on separate circuit board or add-in card disposed within informationhandling system 600, a device that is external to the informationhandling system, or a combination thereof.

Network interface 680 represents a NIC disposed within informationhandling system 600, on a main circuit board of the information handlingsystem, integrated onto another component such as chipset 610, inanother suitable location, or a combination thereof. Network interfacedevice 680 includes network channels 682 and 684 that provide interfacesto devices that are external to information handling system 600. In aparticular embodiment, network channels 682 and 684 are of a differenttype than peripheral channel 672 and network interface 680 translatesinformation from a format suitable to the peripheral channel to a formatsuitable to external devices. An example of network channels 682 and 684includes InfiniBand channels, Fibre Channel channels, Gigabit Ethernetchannels, proprietary channel architectures, or a combination thereof.Network channels 682 and 684 can be connected to external networkresources (not illustrated). The network resource can include anotherinformation handling system, a data storage system, another network, agrid management system, another suitable resource, or a combinationthereof.

Although only a few exemplary embodiments have been described in detailherein, those skilled in the art will readily appreciate that manymodifications are possible in the exemplary embodiments withoutmaterially departing from the novel teachings and advantages of theembodiments of the present disclosure. Accordingly, all suchmodifications are intended to be included within the scope of theembodiments of the present disclosure as defined in the followingclaims. In the claims, means-plus-function clauses are intended to coverthe structures described herein as performing the recited function andnot only structural equivalents, but also equivalent structures.

The above-disclosed subject matter is to be considered illustrative, andnot restrictive, and the appended claims are intended to cover any andall such modifications, enhancements, and other embodiments that fallwithin the scope of the present invention. Thus, to the maximum extentallowed by law, the scope of the present invention is to be determinedby the broadest permissible interpretation of the following claims andtheir equivalents, and shall not be restricted or limited by theforegoing detailed description.

What is claimed is:
 1. A method comprising: negotiating, by atransmitter, with a receiver to lock a transmitter equalizationparameter; selecting a setting adjustment for the locked transmitterequalization parameter; selecting a variation type; applying theselected setting adjustment using the selected variation type, whereinthe applying creates an updated transmitter equalization parameter;re-negotiating the updated transmitter equalization parameter; andperforming data transmission.
 2. The method of claim 1, wherein thelocked transmitter equalization parameter includes a static equalizationrange.
 3. The method of claim 2, wherein the selected setting adjustmentincludes a pre-defined value that is added and subtracted to the staticequalization range to generate an updated equalization range.
 4. Themethod of claim 3, wherein the updated equalization range is applied oneach lane of a peripheral component interconnect express (PCIe) rootport.
 5. The method of claim 2, wherein the selected setting adjustmentincludes different amount of pre-set values, wherein each of the pre-setvalues is added to and subtracted from the static equalization range togenerate different equalization ranges.
 6. The method of claim 5,wherein each of the different equalization ranges is applied to acorresponding lane of a peripheral component interconnect express (PCIe)root port.
 7. The method of claim 1, wherein the setting adjustment isselected from pre-defined values.
 8. The method of claim 1, wherein thevariation type includes a random, a uniform, or a Gaussian distribution.9. The method of claim 1, wherein the applying of the selected settingadjustment using the selected variation type generates non-alignedequalization values.
 10. An information handling system comprising: atransmitter including: a transmitter channel management moduleconfigured to negotiate and to lock a static transmitter equalizationrange; and control logic configured to: select a setting adjustment forthe locked transmitter equalization range; select a variation type;apply the selected setting adjustment using the selected variation type,wherein the applying of the selected setting adjustment creates anupdated transmitter equalization range; instruct the transmitter channelmanagement module to re-negotiate the updated transmitter equalizationrange; and transmit data; and a receiver configured negotiate andre-negotiate with the transmitter in order to receive the updatedtransmitter equalization range, wherein the receiver auto-adapts theupdated transmitter equalization range to receive the transmitted data.11. The information handling system of claim 10, wherein the selectedsetting adjustment includes a pre-defined value that is added andsubtracted to the static equalization range to generate the updatedequalization range.
 12. The information handling system of claim 11,wherein the updated equalization range is applied on each lane of aperipheral component interconnect express (PCIe) root port.
 13. Theinformation handling system of claim 10, wherein the selected settingadjustment includes different amount of pre-set values, wherein each ofthe pre-set values is added to and subtracted from static equalizationrange to generate different equalization ranges.
 14. The informationhandling system of claim 13, wherein each of the different equalizationranges is applied to a corresponding lane of a peripheral componentinterconnect express (PCIe) root port.
 15. The information handlingsystem of claim 10, wherein the variation type includes a random, auniform, or a Gaussian distribution.
 16. A method comprising: receiving,by a transmitter, a static equalization range; selecting a settingadjustment of the static equalization range; selecting a variation type;applying the selected setting adjustment using the selected variationtype, wherein the applying creates an updated transmitter equalizationrange; re-negotiating the updated transmitter equalization range; andtransmitting data.
 17. The method of claim 16, wherein the selectedsetting adjustment includes a pre-defined value that is added orsubtracted to the static equalization range to generate the updatedequalization range.
 18. The method of claim 17, wherein the updatedequalization range is applied on each lane of a peripheral componentinterconnect express (PCIe).
 19. The method of claim 16, wherein theselected setting adjustment includes different amount of pre-set valuesthat are added and subtracted to the static equalization range togenerate different equalization ranges.
 20. The method of claim 19,wherein each of the different equalization ranges is applied to acorresponding lane of a peripheral component interconnect express(PCIe).